Observed dose accuracy using Medrad Intego PET Infusion System

Objectives Determine the accuracy of 18-F FDG doses infused using the Medrad Intego Infusion System.

Methods This study involved the retrospective review of technologist generated data. No patient specific data was recorded. The 100 patients selected for this review had 555 Mbq (15 mCi) prescribed doses and were the first 100 injected patients at the UPMC Hillman Cancer Center.The Intego Infusion System is a computer based infusion pump with an on board dose calibrator. The system uses a calibrated bulk vial of 18F FDG, provided by IBA Molecular. When preparing a dose for injection, the system draws up what it calculates to be 50% of the radiopharmaceutical volume and transports that to the dose calibrator well through disposable tubing. The first 50% is measured and if it is within tolerance, the balance of the dose is prepared. The technologist then has the ability ti infuse or discard the dose.

Results All infused doses were within +/- 10 %. The range was +9.0 % to - 4.53%. 13 out of 100 injections varied by more than 1% from the prescribed activity and 27 exceeded 0.5%. One dose exceeded 5% of the prescribed activity.

Conclusions The Medrad Intego Infusion System is more accurate than using unit doses. In 87% of the injections, the Medrad system was within 1% of the prescribed dose. This increased dosing accuracy will remove a variable from the patient testing and result in a more precise scan.